1. Field of the Invention
The invention concerns a tiltable tray of a sorting conveyor installation for depositing unit loads by means of a swiveling movement from a horizontal transporting position onto a tilting position with a conveyor device on which the tray is arranged.
2. Description of the Prior Art
A tiltable platform or tray of a sorting conveyor installation is known from DE 35 11 936 C2. The sorting conveyor installation essentially includes a plurality of trays which are mostly arranged one directly after the other in the conveying direction and are connected with a conveyor device. The trays are connected with the conveyor device via supporting members, specifically in such a way that they can be tilted transversely to the conveying direction on the one hand and, in so doing, lowered with respect to the supporting member on the other hand. Two knee levers are provided for each tray in addition to the supporting member in order to stabilize the trays in the horizontal transporting position and to execute a movement into an emptying or discharging position which is tilted relative to the transporting position. The knee levers are fastened via joints to the base of the supporting member on the right- and left-hand sides, as seen in the conveying direction, and to the underside of the tray by their other end so as to be at a distance from the tilting axis of the tray. Swivel means, which can be swiveled along guide paths running parallel to the conveying direction, are arranged at the lower ends of the knee levers to produce a controlled tilting process of the tray for depositing the transported unit load onto an adjoining branch conveyor. This causes a folding or bending movement of a preselected knee lever which leads to a tilting movement of the tray in the desired direction. The swivel means of the knee levers are arranged so that when one swivel means is actuated the other swivel means is locked or stopped, since only the knee lever arranged on the side facing the branch conveyor is bent in for the tilting movement. Restoring or reset rollers, for example, can be provided for producing a controlled resetting or righting process of the trays. The reset rollers are arranged one after the other in the conveying direction and so as to ascend proceeding from the discharging station in order to move the tray back into the horizontal transporting position from the discharging position by engaging under the tray as it passes by.
This tiltable platform or tray has proven disadvantageous as the arrangement of the swivel means at the lower ends of the knee levers which project in the direction of the conveyor device increases the overall height. Also, carrying out the lowering process of the tray has proven time-consuming since the knee lever must first be moved out of its rest position in the direction of its extended position before it can be bent in. Moreover, as a result of the lowering of the tilting axis within the supporting member and the slight stretching of the extended knee lever, the unit load merely slides off the tray. Accordingly, a relatively long catching or collecting area is required for the unit load in the region of the discharging station as seen in the conveying direction.